Yarrow oil can help with digestive problems such as flatulence, colic, cramp, indigestion and constipation. On the nervous system, Yarrow oil can be beneficial to stress-related problems, hypertension and insomnia. The skin can also benefit from Yarrow oil; it can heal inflamed wounds, rashes, cuts, eczema, scars, and burns and can promote hair growth, being reputed to prevent baldness.